It was so loose it could have vibrated off, and fallen off no kidding.
I am so glad I noticed this! No positive seal at all.
I am not sure if the rubber seal shrank over the years or if a new seal & cap can be ordered..have not checked yet..anyways it was time for a roadside redneck fix...
I cut one paper gasket and then a thin piece of plastic to fit into cap below the real rubber seal.

I wonder if anyone else has ever discovered this problem?

I may call the dealer & see if a new seal & cap can be ordered tomorrow.
However this repair seems to do the trick !

Usually check mine every now and then, but not as often as I should, I'll inspect mine ASAP, getting ready to storm here.
Very creative fix, looks like something I'd rig up.

As an old farm boy I love haywire fixes, anything to prevent downtime. Good job softride!

2004 Bonne SLE 141k
1971 Chevelle SS 210k

Can that properly be called a "redneck" fix? Seeing as no duct tape was actually used in the repair procedure!

Who says Redneck Repairs are limited to Duct Tape?
According to Urban dictionary ...Under Redneck Engineering..The description is...
The use of unorthodox methods and tools to build, modify or repair machinery, vehicles, etc, usually with little regard to finesse or technique.
In my case it was use whatcha got to get er done & working & sealing properly again...
This repair works so well that I have not even called the dealer for new cap information!